A piezoelectric element has attracted attention as applications such as an actuator for a magnetic head or an MEMS switch. Particularly, a thin film piezoelectric element has high position accuracy and is operable as a high speed actuator (Patent Document 1: Japanese Unexamined Patent Application Publication No. Hei 09-110592). A structure in which a ZrO2 film is deposited on a Si substrate and a Pt film is deposited on the ZrO2 film has been proposed as a stacked film used for a thin film piezoelectric element (Patent Document 1).
Further, a structure in which a ZrO2 film and an Y2O3 film are deposited on a Si substrate, and a Pt film is deposited via a PtO2 film has been proposed (Patent Document 2: Japanese Unexamined Patent Application Publication No. 2015-154015).